Chris Collins/The Star-LedgerAccording to a complaint filed today in Newark federal court, Ruben Alvarado, 27, was a fraud — a man who preyed upon immigrants and others while falsely claiming to be a federal official.

ELIZABETH — When he’d meet with illegal immigrants, authorities say, Ruben Alvarado would often wear a jacket bearing the letters "ICE" — as in the federal Immigration and Customs Enforcement agency — carry handcuffs and strap himself with what looked like a holstered handgun.

He’d tell the immigrants he was an ICE officer who could help them gain legal status in the United States, authorities say.

Then, while collecting multiple fees from them for his "services," Alvarado would take their immigration applications. Later, he’d give them back false approvals — and false hope — on forms that bore his signature as a purported U.S. officer, authorities say.

If anyone complained the documents appeared to be phony, authorities say, Alvarado would threaten them and say that, as an ICE agent, he could have their families deported.

According to a complaint filed earlier this week in Newark federal court, Alvarado, 27, was a fraud who preyed upon immigrants and others while falsely claiming to be a federal official. In all, authorities allege, he collected more than $17,000 from his victims in a scam that ran from September 2009 to May 2011.

Alvarado, of Elizabeth, was arrested early today, U.S. Attorney Paul Fishman said in a statement.

He faces counts of impersonating a federal officer, which carries a maximum penalty of three years in prison, and identification document fraud, which could land him up to 15 years.

Alvarado appeared before U.S. Magistrate Judge Madeline Cox Arleo later today and was released on $50,000 unsecured bond. A call to his public defender was not returned.

In their complaint, federal prosecutors said Alvarado also posed as a Transportation Security Administration officer — and would sometimes produce false photo identification for his victims that said he was a "TSA AIR MARSHAL" and "Fugitive Recovery Agent."

He’d also go after legal immigrants who wanted more permanent status in the United States, prosecutors said, and at some meetings, he displayed a badge reading, "Official Court Officer."

In one instance, prosecutors said, Alvarado promised to help someone get a job at ICE as an agent, demanding more than $2,000 in fees for purported application forms. He then did nothing, instead pocketing the money for himself, prosecutors said.